Once upon a time (the late seventies and early eighties), only about 12 percent of plate appearances ended by the strikeout. Baseball is headed over 20 percent for the first time this year, as a culmination of a decades-long trend.

The question is: What does this development mean for the game?

Just look at how robust the strikeout has become. Here's a graph of the strikeout per plate appearance since 1900:

Before we can decide if this will change soon, we have to decide how bad this is for baseball. Because traditionally, the strikeout has actually been worse of an event than an out on a ball in play. The ball in play has the chance to move a runner, the strikeout very rarely does. And so, when you calculate the value of each event in runs usually scored as a result of that event, as Tom Tango did on his blog InsideTheBook, you get the following 'run values' for some important events:

Runs

Result Description

1.39

Home Run

1.09

Triple

0.77

Double

0.47

Single

0.47

Error

0.39

Advanced

0.35

Hit By Pitch

0.32

Walked

0.30

Bunt

0.28

Balk

0.28

Passed Ball

0.26

Wild Pitch

0.24

Error

0.18

Intentionally Walked

0.16

Stolen Base

-0.20

Sacrifice

-0.23

Bunt Out

-0.24

Ground Out

-0.27

Dropped Third Strike

-0.28

Fly Out

-0.30

Strikeout

-0.31

Fielder's Choice

-0.33

Line Drive

-0.45

Caught Stealing

-0.55

Infield Fly

-0.58

Forced Out

-0.85

Grounded Into Double Play

-1.40

Triple Play

So a strikeout is marginally worse than a fly out and a ground out, mostly because it doesn't usually allow a runner to advance on the basepaths.

But! What if the basepaths are more empty because fewer runners are getting on base? What happens to the value of the strikeout then? Because that's happening right now. Check out the league's on-base percentage since 2000. The study above was run in 2006, and since, we've seen fewer base runners:

So, offense is down and the strikeout is up. There's a bit of a chicken and egg thing here. Is offense down because the strikeout is up, or is the strikeout up because it's less of a bad thing because offense is down?

In practice, it doesn't matter. Strikeouts are less bad now, compared to other outs, than they were even in 2006. John Choiniere took on the subject for Beyond the Box Score and found exactly that. Take a look at this chart from his piece that shows how much worse a strikeout is when compared to a ball in play out.

(via SB Nation)

Offense is down, so the strikeout is not as bad relative to balls in play. So there isn't really a need for teams to value contact more than other skills. So there isn't really a reason for baseball to change.

Except …

It looks like, according to Bill James, the high-contact hitters are more valuable than the high-strikeout hitters this year, and that's a trend that's taken a long time to arrive. According to his last newsletter, low-strikeout hitters are out-producing their high-strikeout colleagues right now:

"In 2011, high-strikeout hitters were 3% LESS effective than low-strikeout hitters. In 2012 they were 1% less effective, and in 2013 high-strikeout hitters were 4% less effective than low-strikeout hitter. In 2013 the high-strikeout group averaged .262 with 19 homers, 73 RBI, whereas the low-strikeout group averaged .279 with 13 homers, 73 RBI, and only a small advantage in the "walks" column for the high-strikeout hitters."

This would be a momentous occasion. Here's another way to think about it: Jack Moore looked at Tony Gwynn's history and found that he's the only hitter in the top ten in career strikeout percentage since 1961 to have shown a weighted offense better than league average. The only one.

Traditionally, your low-strikeout hitters have offered value with their glove or their feet and have had anemic bats. The power in the high-whiff bats has more than offset that, and so there has been little pressure on hitters to strikeout less, only pressure on pitchers to strike more batters out.

Take a look at the top ten hitters by strikeout rate from 2000-2004:

Name"

PA

HR

SB

BB%

K%

AVG

OBP

SLG

wRC+

BsR

Off

Def

WAR

Juan Pierre

3037

7

210

6.1%

5.5%

0.312

0.361

0.380

90

24.6

-16.3

36.5

11.8

Fernando Vina

2352

18

50

5.6%

6.0%

0.282

0.347

0.377

93

-1.7

-22.5

16.2

6.9

Mark Grace

1677

36

4

13.4%

6.5%

0.273

0.372

0.421

103

-3.6

3.5

-11.7

4.5

Eric Young

2858

31

158

8.5%

6.8%

0.279

0.349

0.388

94

14.6

-7.7

-8.9

7.5

Placido Polanco

2664

48

42

5.1%

7.0%

0.298

0.343

0.417

99

3.3

0.2

67.5

15.3

Paul Lo Duca

2450

57

9

6.5%

7.0%

0.287

0.342

0.428

105

-14.2

3.1

55.1

13.6

Jason Kendall

3279

36

69

8.6%

7.2%

0.302

0.380

0.398

107

-5.1

23.8

38.2

16.4

David Eckstein

2520

17

82

6.6%

7.9%

0.278

0.347

0.353

91

13.4

-14.7

27.9

9.9

Randall Simon

1425

44

4.4%

8.0%

0.278

0.313

0.421

90

-6.2

-24.2

-40

-1.6

Orlando Cabrera

3128

61

88

6.6%

8.1%

0.270

0.318

0.411

84

15.6

-50.6

40.9

9.3

There are valuable players on this list, but only Mark Grace and the two catchers managed to be league average with their bats. (Weighted runs created plus weights a player's outcomes at the plate by their value with respect to runs scored, and then puts that on a scale where 100 equals average). Most of these players added value with their feet (Juan Pierre and Eric Young) or their gloves (Placido Polanco, David Eckstein and Orlando Cabrera).

Let's look at the list since 2010 as a comparison.

Name

PA

HR

SB

BB%

K%

AVG

OBP

SLG

wRC+

BsR

Off

Def

WAR

Juan Pierre

2214

5

155

5.6%

6.4%

0.278

0.331

0.329

81

24.1

-24.9

-21.4

2.6

Jeff Keppinger

1844

25

5

5.8%

7.2%

0.285

0.327

0.381

95

-8.5

-18.2

-10.4

3.1

Placido Polanco

1869

14

10

6.2%

7.9%

0.277

0.326

0.344

84

-34.2

37.4

6.4

Marco Scutaro

2370

27

20

7.4%

8.0%

0.294

0.347

0.395

102

2.9

8.9

4.5

9.4

Norichika Aoki

1554

18

57

7.7%

8.0%

0.283

0.350

0.385

104

-2.2

5.1

-6.2

5

Victor Martinez

2134

66

4

8.1%

8.8%

0.313

0.366

0.482

127

-18

48.7

-30.8

9.3

Carlos Lee

1917

51

10

8.0%

8.8%

0.261

0.321

0.410

98

-13.4

-17.3

-30.4

1.3

Jose Reyes

2629

45

140

7.4%

9.2%

0.296

0.347

0.442

115

16.6

61.2

7.3

16.1

Alberto Callaspo

2449

39

17

9.4%

9.2%

0.264

0.332

0.365

95

-7.6

-20.6

19.2

8.3

Andrelton Simmons

1145

25

9

6.0%

9.3%

0.254

0.300

0.388

89

-1.2

-15

56.8

8.2

It's not that there's one more name on this list than the last one, that wouldn't be any sort of significant finding. It's that there are more sluggers on this list. Look at Victor Martinez, Carlos Lee, and even Andrelton Simmons: all three have power. Martinez far outstrips anyone on the other list from just a couple of decades ago. And sitting in 11th on this list is Vladimir Guerrero, who did a pretty good Victor Martinez impression himself.

The strikeout is getting less bad, relative to other outs, as offense goes down. That's true. But what's also true is that the strikeout hasn't been much worse than an out in play for a couple of decades. So baseball isn't changing because of the value of a strikeout.

But baseball might be changing anyway. Perhaps a few high-contact sluggers will provide a roadmap for a sport that is hung up on comparisons. As teams develop and scout players, it might become easier for the next high-contact young player to advance while playing his own way because Victor Martinez is kicking butt right now. Now he can be the next V-Mart instead of being encouraged to swing harder and go for more power at the expense of his nice strikeout rate.

Baseball changes. Why it changes might be impossible to nail down.

* * *

Eno Sarris writes about baseball at FanGraphs most of the time. He also started BeerGraphs for the beer nerds out there. He doesn't always play daily fantasy, but when he does, he plays it at DraftStreet.com.